Deputy Group Editor, Laura Griffiths, speaks to Daniel Büning, Head of Global Strategy at Berlin-based large-format 3D printing company, BigRep, about its recently announced partnership with Etihad Airways Engineering and why functional integration and digital smartness are the future of additive manufacturing for aerospace.

Hi Daniel. BigRep has already established itself within the transport sector through a successful collaboration with railway giant, Deutsche Bahn, tell us about how BigRep’s venture into aerospace came about with Etihad Airways Engineering.

DB: Around 18 months ago we were looking for strategic partners in the aviation industry, although we did not have anyone suitable in our portfolio at that time. We were specifically looking for a partner that would be allowed to print high-performance engineering plastics such as Ultem. We took the decision to partner with a renowned aerospace player such as Etihad Airways, while in parallel working on the next generation of machines to process aviation grade materials. Once we have a machine to print these polymers it will help us certify the materials and the process for the EASA (European Aviation Safety Agency).

LG: There are numerous well-known benefits for AM in the aerospace sector in terms of light-weighting, component consolidation, spare part manufacture, etc. Can you talk more specifically about the kinds of things you’re working on with Etihad?

DB: We are currently working with the innovation unit of Etihad Airways Engineering to identify parts within the cabin – predominantly large format parts – that could be candidates for 3D printing. It could be headrests, it could be side wall panels, it could be part of the seats or entertainment system. The core idea is to work with their lead designers and engineers to establish a novel digital workflow for AM cabin design. The biggest problem is to open up the minds of engineers to think AM in order to unfold the full potential of the technology. Our current strategy is to work on design concepts that are basically non-flying but can be built into test aircraft and mock ups.

In this context, we are also heavily trying to utilise dual extrusion technology for the embedding of electrical sensors. Already today we are able to put some sort of electronic or, let’s call it ‘digital smartness’, into parts with our BigRep systems in combination with digitally tailored design methods.

LG: You mention one of the biggest challenges for industry is getting engineers to think for AM. Do you find that big companies like Etihad are receptive to these new technologies and changing their workflow?

DB: This is just one example of our long-term plan when it comes to aerospace applications and Etihad Airways Engineering is our first choice of partner because they are very, very fast moving. Etihad was really the first one that immediately understood the value of such a partnership in the long run. They appreciate it’s not just about [us] giving them a machine that is capable to print Ultem or a similar material, but it’s also about looking into the design and smartness capabilities of AM for aerospace.”

LG: Learning to design for AM is certainly a challenge but for aerospace in particular, certification is often a barrier. Have you faced any challenges in that area so far?

DB: Etihad Airways Engineering is the first Airline MRO (Maintenance, Repair and Overhaul) that is permitted by the EASA to certify, manufacture and fly 3D Printing parts. This was also a major reason why we partnered with them. Imagine you have an aircraft that is 30-years-old and there is a need to refurbish or retrofit them every five to 10 years. Every one of those parts have to be certified. This is a major problem if you are not able to do it by yourself or with a certified partner.

LG: How does the partnership work, does Etihad currently have BigRep machines in-house?

DB: In the near future Etihad will get systems which will be located in Abu Dhabi. They have a beautiful Innovation Centre and their own testing facility, so we can print test parts and put it in the flame lab or put it in the destructive testing machines – they have everything we need to jointly go through the process. That is also the reason why we decided to relocate the machines to Abu Dhabi, because we can use them for our design workshops and we can do all the testing on site.

LG: You said you are working to identify suitable parts within the cabin – are there any areas you are focussing on first where you believe AM will offer the biggest benefits?

DB: For me, as an innovation director, I was always sure that AM would really take off if you have functional integration. For example, with dual extrusion and the right materials such as conductive or capacitive, it is possible dramatically decrease the manufacturing process by embedding structural and functional performance within a single process chain. In my opinion this is really the way to go, and that’s why BigRep is pushing hard on this.

If we tried to compete with traditional manufacturing technologies, such as injection moulding or CNC milling, those will always appear to be cheaper and they will mostly be established and certified. OEMs, Tier 1 and Tier 2 suppliers will not accept AM as a novel superior technology until the industry comes up with innovative applications. It is all about the creation of a value-add whether it´s about functional integration or reducing production cost and time by reducing assembly time for example.

Within the metal AM industry, for example, digitally optimised parts, which are characterised by weight reduction and bionic design principles, are already widely established. We have to get into these kinds of industry applications for the polymer AM industry. For BigRep, of course, it’s all about large-format applications. We have very exciting new systems coming up this year I am not allowed to speak about, but it will allow for huge cabin parts.

LG: Can you talk more about what the integration of “digital smartness” means and how you are going to use BigRep technology to achieve this?

DB: “In recent months, we were deeply looking into what I call “hybrid additive manufacturing”. This means you 3D print using an off the shelf 6-axis industrial robot that will allow you to print onto half-finished parts independent of its geometry or size. For example, imagine a carbon fibre prepreg side panel from an aeroplane – this is an industry standard state of the art technology – with our new approach you are able to print basically anything you want onto it – I call this a digital value add-on.

Scanning each part is the first step, the result is a so-called “digital twin”. Having the special information about the location and size of the actual part we are then able to print sensor material, ornaments, or electric tracks, or antennas onto the part.

LG: The partnership was first announced in April. How far along in the development process are you? Have you produced any test pieces you can tell us about?

DB: As a first proof-of-concept we made a full-scale print of an Airbus A320 sidewall on the BigRep ONE. This part was then scanned by the robot and in a consecutive step the extrusion process starts. In the images (above) you can see the ornament that says ‘Etihad Airways’, which was printed with a robot. Next to the ornament we also printed conductive tracks and antennas on top of the part. This is to show the potential of this approach by adding functionality on existing objects and semi-finished products.

DB: This research was conducted by the NOWlab@BigRep, which is BigRep’s internal innovation department – my team. This is another of BigRep’s visionary approaches having its own innovation department that has the freedom to work on such a future project. So the NOWlab is looking five, 10 years from now and works on projects that will set new trends in AM that won’t necessarily be released tomorrow.

Read more in our AM in aerospace feature in the latest issue of TCT Magazine. Download the digital version for free or subscribe to receive future issues of our four print publications here.